Generalized social anxiety disorder (GSAD) is a public health problem. Many forms of treatment are at least moderately successful, but there is clearly room for improvement. One potential area for improvement is in reducing interpersonal impairment. Beyond the fact that it exists, little is known about the interpersonal impairment conferred by GSAD. This proposal focuses on behavioral economic tasks as a potential means of assessing interpersonal impairment beyond self-report. A major problem with existing studies of behavioral economic tasks is that the tasks used lack sufficient evidence of validity: Direct evidence that such tasks correlate with actual interpersonal behavior is lacking. The proposed study tests whether participants with GSAD differ from participants without on the iterated prisoner's dilemma. It further tests whether behavior on this behavioral economic task predicts face-to-face interpersonal behavior. There are two expected end results of this research. The first is a clearer understanding of the nature of the interpersonal impairment in GSAD. The second is a validated behavioral economic method of assessing interpersonal impairment. If the iterated prisoner's dilemma is found to relate to face-to-face interaction, further examination of the biological substrates of social behavior using such tasks will be justified. The task could also be used to assess the efficacy of existing treatment in reducing interpersonal impairment, both in GSAD and other disorders. In addition, it could be used to evaluate novel interventions designed specifically to improve interpersonal functioning. Such projects are necessary to the full realization of Strategic Objective 3 of the NIMH strategic plan, which calls for addressing the diverse needs of people with mental disorders, moving beyond measures of symptoms alone. PUBLIC HEALTH RELEVANCE: Social anxiety, and more particularly generalized social anxiety disorder (GSAD), is a public health problem with no ideal treatment. The problem is described as fundamentally interpersonal, and our lack of information regarding interpersonal dysfunction in the disorder might be one reason our treatments are often not successful. The current project will provide information about interpersonal impairment that may improve treatment of GSAD and enhance our ability to understand interpersonal impairment conferred by other disorders.